1. Field of the Invention
The present invention relates to an apparatus for auto-focusing detection, a camera applying the same, and a method for calculating a distance to a subject, and more particularly, to an apparatus for auto-focusing detection, a camera applying the same, and a method for calculating a distance to a subject, in which a focus is automatically controlled using an image pickup sensor without using a separate sensor.
2. Description of the Related Art
With the spread of multimedia devices and Internet, users frequently store photographs taken by themselves in a multimedia device or upload them in Internet blog. Consequently, camera ownership has increased in recent years.
Recently, cameras include an auto focusing (AF) function, which enables automatic focus adjustment. In general, AF systems use a contrast method or a phase difference detection method.
In the contrast mode, since the amount of defocus cannot be measured directly, measurements should be performed several times.
In the phase difference detection mode, although focusing is performed in a short time, a dedicated detection unit is required, with a separate optical system that guides light for focusing detection.
In this environment, a pupil split type auto focusing detection apparatus has been developed. Since the pupil split type apparatus detects a focus using an image sensor, it does not require a separate sensor for auto focusing detection.
An example of the pupil split type apparatus splits light into a time series of samples.